// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package des implements the Data Encryption Standard (DES) and the
// Triple Data Encryption Algorithm (TDEA) as defined
// in U.S. Federal Information Processing Standards Publication 46-3.
//
// DES is cryptographically broken and should not be used for secure
// applications.

// package des -- go2cs converted at 2022 March 13 05:34:15 UTC
// import "crypto/des" ==> using des = go.crypto.des_package
// Original source: C:\Program Files\Go\src\crypto\des\const.go
namespace go.crypto;

public static partial class des_package {

// Used to perform an initial permutation of a 64-bit input block.
private static array<byte> initialPermutation = new array<byte>(new byte[] { 6, 14, 22, 30, 38, 46, 54, 62, 4, 12, 20, 28, 36, 44, 52, 60, 2, 10, 18, 26, 34, 42, 50, 58, 0, 8, 16, 24, 32, 40, 48, 56, 7, 15, 23, 31, 39, 47, 55, 63, 5, 13, 21, 29, 37, 45, 53, 61, 3, 11, 19, 27, 35, 43, 51, 59, 1, 9, 17, 25, 33, 41, 49, 57 });

// Used to perform a final permutation of a 4-bit preoutput block. This is the
// inverse of initialPermutation
private static array<byte> finalPermutation = new array<byte>(new byte[] { 24, 56, 16, 48, 8, 40, 0, 32, 25, 57, 17, 49, 9, 41, 1, 33, 26, 58, 18, 50, 10, 42, 2, 34, 27, 59, 19, 51, 11, 43, 3, 35, 28, 60, 20, 52, 12, 44, 4, 36, 29, 61, 21, 53, 13, 45, 5, 37, 30, 62, 22, 54, 14, 46, 6, 38, 31, 63, 23, 55, 15, 47, 7, 39 });

// Used to expand an input block of 32 bits, producing an output block of 48
// bits.
private static array<byte> expansionFunction = new array<byte>(new byte[] { 0, 31, 30, 29, 28, 27, 28, 27, 26, 25, 24, 23, 24, 23, 22, 21, 20, 19, 20, 19, 18, 17, 16, 15, 16, 15, 14, 13, 12, 11, 12, 11, 10, 9, 8, 7, 8, 7, 6, 5, 4, 3, 4, 3, 2, 1, 0, 31 });

// Yields a 32-bit output from a 32-bit input
private static array<byte> permutationFunction = new array<byte>(new byte[] { 16, 25, 12, 11, 3, 20, 4, 15, 31, 17, 9, 6, 27, 14, 1, 22, 30, 24, 8, 18, 0, 5, 29, 23, 13, 19, 2, 26, 10, 21, 28, 7 });

// Used in the key schedule to select 56 bits
// from a 64-bit input.
private static array<byte> permutedChoice1 = new array<byte>(new byte[] { 7, 15, 23, 31, 39, 47, 55, 63, 6, 14, 22, 30, 38, 46, 54, 62, 5, 13, 21, 29, 37, 45, 53, 61, 4, 12, 20, 28, 1, 9, 17, 25, 33, 41, 49, 57, 2, 10, 18, 26, 34, 42, 50, 58, 3, 11, 19, 27, 35, 43, 51, 59, 36, 44, 52, 60 });

// Used in the key schedule to produce each subkey by selecting 48 bits from
// the 56-bit input
private static array<byte> permutedChoice2 = new array<byte>(new byte[] { 42, 39, 45, 32, 55, 51, 53, 28, 41, 50, 35, 46, 33, 37, 44, 52, 30, 48, 40, 49, 29, 36, 43, 54, 15, 4, 25, 19, 9, 1, 26, 16, 5, 11, 23, 8, 12, 7, 17, 0, 22, 3, 10, 14, 6, 20, 27, 24 });

// 8 S-boxes composed of 4 rows and 16 columns
// Used in the DES cipher function
private static array<array<array<byte>>> sBoxes = new array<array<array<byte>>>(new array<array<byte>>[] { {{14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7},{0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8},{4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0},{15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13},}, {{15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10},{3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5},{0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15},{13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9},}, {{10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8},{13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1},{13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7},{1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12},}, {{7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15},{13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9},{10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4},{3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14},}, {{2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9},{14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6},{4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14},{11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3},}, {{12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11},{10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8},{9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6},{4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13},}, {{4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1},{13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6},{1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2},{6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12},}, {{13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7},{1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2},{7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8},{2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11},} });

// Size of left rotation per round in each half of the key schedule
private static array<byte> ksRotations = new array<byte>(new byte[] { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 });

} // end des_package
